the first post I copied (mine) tells how to get the number you need to set to.I have hand calculated the MPG's on my last four tank fill-ups and compared it to the truck's readings. My actual calculations are between 1- 1.5 mpg's less than what the truck displays. I am looking to change the data points in the computer through the "engineering" mode. Has anyone completed this before?
the second part, by “Bandito” tell how to get into Engineering Mode.
No real procedure to exit other than to turn the truck off.
make a note of what the dash is reading now, and it should change a bit after the change.
Takes about two minutes to adjust this.
hand calculate your mileage per fillup
divide that number by what the truck tells you you got.
Display shows 21.3
actual comes out to 19.6
access engineering mode ( I forgot how since I’ve done it—simple tho)
change fuel AFE BIAS setting to 920 ——it should be set to 1000 factory
there are a couple of videos posted around here that show you how
edited to correct area of engineering mode from DTE to AFE BIAS
Just for convenience, to get into Engineering Mode, simply hold down the OK button on the right side of the steering wheel and start the truck. The center display will indicate that you are in EM and you can release the OK button. A press on the up arrow will land you on the AFE BIAS (Average Fuel Economy Bias?) page where you can make your adjustment.
After one or two adjustments, I have always been able to get within .1 mpg of the hand-calculated value which means I know the truck is telling me the truth. Before this adjustment, the truck was 1.1 mpg optimistic.